Optical pickup and optical read/write apparatus
AssigneePanasonic Corporation
InventorsTomoaki Tojo, Yohichi Saitoh, Kazuo Momoo
Life of this patent
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Abstract
An exemplary optical pickup comprises: first, second and third photosensitive elements which are arranged to respectively receive a main light beam and first and second sub-light beams reflected from an optical storage medium; and fourth and fifth photosensitive elements which are arranged to receive the rest of the light that has also been emitted from a light source but has not been reflected from the optical storage medium. A signal that has been written on the optical storage medium with the main light beam for writing is read by performing an arithmetic operation on the signal output of the second or third photosensitive element and that of the fourth photosensitive element.
Claims10
An optical pickup comprising:
- a light source which emits light;
- an optical power modulator which modulates the optical power of the light source;
- an optical element which splits the light that is emitted from the light source into a main light beam for writing and at least two sub-light beams including first and second sub-light beams;
- an optical system which condenses the main light beam and the first and second sub-light beams onto the same track on an optical storage medium, thereby forming a main spot and first and second sub-spots on the same track;
- first, second and third photosensitive elements which are arranged so as to respectively receive the main light beam and first and second sub-light beams that have been reflected from the optical storage medium;
- fourth and fifth photosensitive elements which are arranged so as to receive the rest of the light that has also been emitted from the light source but has not been reflected from the optical storage medium;
- and
- an arithmetic section which reads a signal that has been written on the optical storage medium with the main light beam for writing by performing an arithmetic operation on the signal output of the second or third photosensitive element and the signal output of the fourth photosensitive element.
An optical read/write apparatus comprising an optical pickup, a motor which drives an optical storage medium, and a control section which controls the optical pickup,
- wherein the optical pickup comprises:
- a light source which emits light;
- an optical element which splits the light that has been emitted from the light source into a main light beam for writing and at least two sub-light beams including first and second sub-light beams;
- an optical system which condenses the main light beam and the first and second sub-light beams onto the same track on the optical storage medium, thereby forming a main spot and first and second sub-spots on the same track;
- first, second and third photosensitive elements which are arranged so as to respectively receive the main light beam and first and second sub-light beams that have been reflected from the optical storage medium;
- and
- fourth and fifth photosensitive elements which are arranged so as to receive the rest of the light that has also been emitted from the light source but has not been reflected from the optical storage medium, and
- wherein the control section includes:
- an optical power modulator which modulates the optical power of the light source;
- and
- an arithmetic section which reads a signal that has been written on the optical storage medium with the main light beam for writing by performing an arithmetic operation on the signal output of the second or third photosensitive element and the signal output of the fourth photosensitive element.
Dependencies are inferred from the claim text.